I need a method that takes as input a double between $0$ and $180$ and outputs a double between $-1$ and $1$ with $0$ mapping to $-1$ and $180$ mapping to $1.$ Some of the versions below are buggy. Which is correct? You're expected to test out these methods. No input validation is needed:

Question $1$ options:

public static double angleToInterval$($double angle$)\{$

return $-1-$ angle$/90\mathrm{.}0$;

$\}$

public static double angleToInterval$($double angle$)\{$

return $1-$ angle$/90\mathrm{.}0$;

$\}$

public static double angleToInterval$($double angle$)\{$

return angle$/90\mathrm{.}0-1$;

$\}$

public static double angleToInterval$($double angle$)\{$

return angle$/90\mathrm{.}0+1$;

$\}$